Calculation of Induced Velocity in Normal Operating Conditions for Vertical Climb and Hover, Autorotation Regime, Vortex Ring State, and Forward Flight Regime for the Sikorsky S-70 Black Hawk Helicopter

This paper investigates the variations of induced velocity in the main flight regimes of the Sikorsky S-70 Black Hawk helicopter, an essential parameter in the aerodynamic performance analysis of the main rotor. Based on ideal theory, the study relies on the momentum theorem and analytical methods used in fluid dynamics. The aim is to establish the mathematical expressions of the induced velocity in the helicopter's primary flight regimes. The analysis of these regimes highlights velocity variations and their impact on the helicopter's performance. The results obtained can be used to optimize rotor design, leading to improved energy efficiency